Coincidentally I am just doing a pin striped kilt, light grey with a slightly wavy white stripe where the grey is not printed.

I did use a ruler and tape measure when starting out, so as to get the aprons right, but to get the selveges always to meet at the under fold edge of a pleat I jiggled the proposed fold points one stripe at a time so as to obtain the required meeting of edges. I counted the number of stripes available rather than the length of the cloth, and put in an extra pleat, that is one more than I was planning for, so as to get everything to fit almost perfectly. There is an extra stripe on one side, but it would be difficult to spot where.

If you sew the edges together up as far as the fell and then allow the edges to move so as to give you the taper you can sew the rest of the join up to the waist to suit, or if you are going to cut out the back of the fell, just leave it.

I always try to make a selvage join the under fold edge because it is usually a bit stiffer than the rest of the fabric. If it has to go anywhere else I cut off the selvage and make the seam in the fabric. Seams which are going to be under only one layer of fabric usually show, so I try to avoid those now.

Making a kilt from fabric cut across the width is rather different from one made from a single length with a selvage edge - something which I am begining to regard as a luxury project.

However - creating a pieced kilt is a most satisfying thing when it works.

Good luck with the jacket project - I find jackets the most difficult of garments, even more so that coats. The shoulder padding is essential, as is getting the right amount of stiffness in the lapels and collar. It does not have to be much, just right, absolutely right.